To season copper canelé molds, wash and dry them, then rub or brush the molds all over (inside and out) with a neutral oil like canola or vegetable oil. Place them on a baking sheet, open side up, and bake in a 350-degree-F oven for 1 hour. Flip the molds and bake for 15 more minutes. Turn off the oven and let the molds cool in the oven. They should now be seasoned and ready to use. After the initial seasoning, don’t wash the molds – just wipe them clean with a towel. (If you must wash a mold because something has stuck to it you should season the mold again.)